APCSMART-OLD(8)

✨ APCSMART-OLD(8) ✨

okay bestie, so this is a page from the NUT Manual (Network UPS Tools, the whole shebang) and it's all about apcsmart-old — the driver that talks to American Power Conversion Smart Protocol UPS equipment. yes, the big beige bricks that keep your homelab alive. 💖

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🌸 NAME 🌸

apcsmart-old — driver for American Power Conversion Smart Protocol UPS equipment. it's giving "your UPS, but make it vintage." 👑

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🎀 SYNOPSIS 🎀

apcsmart-old -h

apcsmart-old -a UPS_NAME [OPTIONS]

heads up, bestie: this man page only spills the tea on the hardware-specific stuff for the apcsmart-old driver. for the core driver deets — the general stuff that every driver shares — go read nutupsdrv(8). 🫶

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🦋 SUPPORTED HARDWARE 🦋

apcsmart-old should recognize all recent APC models that use a serial protocol at 2400 bps. lowkey iconic speed, i know. that's mainly the Smart-UPS, Matrix-UPS and Back-UPS Pro lines. 💅

the driver attempts to support every bell and whistle of the APC reporting interface — whether or not this is strictly sensible. and honestly? respect. it's giving overachiever energy. ✨

some older hardware may only report a handful of variables. that's usually not a bug — they just don't support anything else, bestie. it's not them being lazy, it's them being old. 🧚

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🌈 CABLING 🌈

by default, this driver expects to see a 940-0024C cable, or a clone of one. periodt. 💜

you can switch over to the 940-0095B dual-mode cable support with the cable= definition described below (it's in EXTRA ARGUMENTS, keep scrolling bestie). 🎀

if your 940-0024C cable is broken or missing (rip 😭), use this diagram to build a clone:

https://www.networkupstools.org/cables/940-0024C.jpg

diagram said "build your own." crafty queen behavior. 🛠️

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💖 EXTRA ARGUMENTS 💖

this driver supports the following optional settings in the ups.conf(5):

• cable=940-0095B — configure the serial port for the APC 940-0095B dual-mode cable. that's it, that's the setting. ✨
• sdtype=num — use shutdown type num, according to this table:
  • 0 — soft shutdown or powerdown, depending on battery status
  • 1 — soft shutdown followed by powerdown
  • 2 — instant power off
  • 3 — power off with grace period
  • 4 — "force OB" hack method for CS 350

okay so the vibes of these modes matter, so listen up:

modes 0 and 1 will power up the load when power returns. 🌞 modes 2 and 3 will keep the load turned off when the power returns. 💀 so like, pick wisely, because one of these is "welcome back bb" and the other is "we're not doing that again."

mode 4 exploits an oddity in the CS 350 models, since they only seem to support the S command — but then only when running on battery. as a result, the driver will force the UPS to go on battery if necessary before sending the shutdown command. this ensures that the load gets reset. it's a whole hack, no cap, and it's working. 🔥

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💀 BUGS 💀

some older APC UPS models return bogus data in the status register during a front panel test. this is usually detected and discarded, but some other unexpected values have occasionally slipped through. 🙈 not me trusting a status register that lies during tests, i guess.

APC UPS models with both USB and serial ports require a power cycle when switching from USB communication to serial — and perhaps vice versa. so yeah, unplug and plug it back in, bestie. that's the fix. that's always the fix. 😭

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👑 AUTHORS AND HISTORY 👑

Nigel Metheringham <Nigel.Metheringham@Intechnology.co.uk> — drawing heavily on the original apcsmart driver by Russell Kroll. shoutout to the OGs, fr fr. 🫶

this driver was called newapc for a time, and was renamed in the 1.5 series. glow-up era. ✨

in 2.6.2 the driver was renamed to apcsmart-old, being superseded by an updated version with new features which currently holds the apcsmart name. so yes, this one is literally the old one — the name is not subtle, and honestly? we love a driver that knows what it is. 💅

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⭐ SEE ALSO ⭐

The core driver:

• nutupsdrv(8)

Internet resources:

• The NUT (Network UPS Tools) home page:

https://www.networkupstools.org/historic/v2.8.5/

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and that's the whole page, bestie!! 💖 this was Network UPS Tools 2.8.5, dated 10/07/2026, and it lives at APCSMART-OLD(8) in the NUT Manual — old name, immaculate vibes, still out here shutting down UPSes with grace periods. slay. 🌸🎀🦋